Windshield panes for the cockpit of an aircraft are installed from the inside or from the outside.
If the panes are installed from the outside, the glass is pressed against a frame composed of or attached on the uprights and crossbeams of the fuselage at the cockpit or on its skeleton.
The panes are placed in contact with the frame by means of exterior window pane retainers, which in turn are fastened to the crossbeams and uprights of the fuselage by means of screws or rivets.
This type of installation with window pane retainers leads to a reduction of the useful area of the pane, and to a thickening of the posts between two panes, which reduces the field of vision of the pilots, especially because the fastening of the retainers of two adjacent panes is done on two adjacent lines on the uprights of the cockpit.